You can make die sets that will work with various types of angle iron. They are actually one of the easier die sets to make, as they don't require cutting a curve like the round tubing dies do. When I get around to making a set, I will update the instructable. You could definitely make a window well cover with the proper die set. If you can tell me what specific type of angle iron you want to use, I can draw you a blueprint of the die you would need to make.

The dies were actually the best part of the HF roller, I am temporarily reusing some of them until I get around to making full sets.

I talked about that one in the introduction. It broke the first time I used it, and even before it broke, it didn't do a very good job.

As someone who once had to solve the problem of not having the correct arbor myself, there is a better way to do this. First, use a bolt with the correct thread. The reason your threads are not fitting properly is because you are using a coarse thread, but because a hole saw is a high-torque application, it uses a fine thread, I know one of the standard sizes you will find on hole saws is 1/2"-20 tpi. If you are using standard coarse threads, a 1/2" thread only has 13 tpi. Aso buy a fine thread hex nut, and before you put the hole saw on, screw the hex nut onto the bolt. Now thread on your hole saw, and once it is threaded on fully, tighten the nut against the hole saw, this will make it so it doesn't slip without messing up the threads. Finally, if you want to get fancy, cut ...

As someone who once had to solve the problem of not having the correct arbor myself, there is a better way to do this. First, use a bolt with the correct thread. The reason your threads are not fitting properly is because you are using a coarse thread, but because a hole saw is a high-torque application, it uses a fine thread, I know one of the standard sizes you will find on hole saws is 1/2"-20 tpi. If you are using standard coarse threads, a 1/2" thread only has 13 tpi. Aso buy a fine thread hex nut, and before you put the hole saw on, screw the hex nut onto the bolt. Now thread on your hole saw, and once it is threaded on fully, tighten the nut against the hole saw, this will make it so it doesn't slip without messing up the threads. Finally, if you want to get fancy, cut the head off the bolt and you can chuck it up in a drill and drill the hole a lot faster than doing it by hand. Just start slow until you have a bit of a groove or the hole saw will bounce all over the place.

How fast does it go?Also, time for a nostalgic trip down memory lane... this brings back memories of my first motorized bicycle build. I also used a chainsaw engine, although I ran a separate chain to the rear wheel on the left side so that I could still pedal assist on the hills. I've long since trashed that first bike, but once I built the first one, I was hooked. Now I've got these, among many others, and I'm pushing 70 mph with the black one lol...

I would not recommend welding the mount to the frame, as if you weld it you can't just loosen the bolts and slide it around to adjust the chain tension, and I have had horrible experience with chain tensioners. If you tried to run a 7.2:1 gear ratio, the bike would never have enough power to move. I run about 13:1 on mine, I weigh 155 lbs. 3500 rpm max is about what you'd get if you left the governor intact, I manage to get about 7200 rpm max on mine, but this is after several mods which are not covered in this instructable. The original flywheel flew apart at about 7000 rpm, and the valves started to float and limit the rpm a few hundred rpm below that, I've since replaced the flywheel with a better one, and installed different valve springs. I've also sanded down my cylinder head for ...

I would not recommend welding the mount to the frame, as if you weld it you can't just loosen the bolts and slide it around to adjust the chain tension, and I have had horrible experience with chain tensioners. If you tried to run a 7.2:1 gear ratio, the bike would never have enough power to move. I run about 13:1 on mine, I weigh 155 lbs. 3500 rpm max is about what you'd get if you left the governor intact, I manage to get about 7200 rpm max on mine, but this is after several mods which are not covered in this instructable. The original flywheel flew apart at about 7000 rpm, and the valves started to float and limit the rpm a few hundred rpm below that, I've since replaced the flywheel with a better one, and installed different valve springs. I've also sanded down my cylinder head for better compression, welded a custom exhaust pipe which has as few curves as possible, and ported the engine. If you just do the mods in this instructable, the valves will start to float around 6500 or so, and the engine won't rev higher. Stronger valve springs fix that, but then you risk blowing up the flywheel as I found out. But it's totally worth it in my opinion, I'm getting probably at least 5.5 hp out of it, maybe 6, I can hit 40 on level ground, and go up almost any hill with no pedal assist. However, if you don't want to shell out big bucks for a somewhat marginal increase in power (the red one is now my race bike, where every bit counts) then don't bother with all that. The factory cooling system is fine, I have had no issues with it. Just remove the cooling tin because it restricts air flow around the engine, and we are cooling it with the air moving past the engine as we ride it. Also, if you're like me, and bigger is better, and too much is never enough, consider building one with the 212cc predator instead. Then you can run a 10:1 gear ratio no problem and go 50 mph. Or, if you're also as crazy as me, put a 125cc lifan on a stretch cruiser and you can keep up with the cars on the freeway.

Also it's not really that loud at 30 mph even revving around 5000 rpm. And I get about 150 mpg cruising at 30.

I contacted AGK, and apparently they no longer carry the premade exhaust pipes for the 79cc predator engine. I'll update the instructable within a few weeks, going through the process of making your own exhaust pipe, if you don't have access to a TIG or acetylene welder or find that it's too expensive to have a welding shop do it, PM me and I'll see about making one for you.

There used to be 2 pipes that would work on affordablegokarts.com, however I'm no longer seeing them. I'll do some digging, and if I can't find one, I could make you one or tell you how to make one if you've got a friend who has a TIG or acetylene welder.

Sorry to break it to you, but you got a pretty bad bike to motorize. I'd return it if you still have the receipt and instead look for an old mountain bike on craigslist. If you do use it, you'll need to replace the rear wheel, there's no way to attach a sprocket to it, and the springer fork, which is super flimsy, and add some brakes. A rear coaster brake as your only brake is going to get you killed. When you replace the springer fork you should get one with disc brake mounting tabs and add a nice front disc brake. Buy (or build) a jackshaft such as the ones shown in the instructable. GTC Manufacturing sells one for a go-kart that will work if you swap out the gears. Alternatively you can build one with steel plates and pillow block bearings.As for the other stuff, you still need a lot...

Sorry to break it to you, but you got a pretty bad bike to motorize. I'd return it if you still have the receipt and instead look for an old mountain bike on craigslist. If you do use it, you'll need to replace the rear wheel, there's no way to attach a sprocket to it, and the springer fork, which is super flimsy, and add some brakes. A rear coaster brake as your only brake is going to get you killed. When you replace the springer fork you should get one with disc brake mounting tabs and add a nice front disc brake. Buy (or build) a jackshaft such as the ones shown in the instructable. GTC Manufacturing sells one for a go-kart that will work if you swap out the gears. Alternatively you can build one with steel plates and pillow block bearings.As for the other stuff, you still need a lot of parts. Air filter, exhaust pipe, throttle, throttle linkage, lots of other stuff, etc.You also have a hub adapter, which means that mag wheels are unfortunately out unless you want to buy another adapter. Although buying mag wheels and an adapter might be cheaper than getting a custom built spoked wheel strong enough to hold up to the motor. You can get a set of super sturdy mag wheels with disc brake mounts for about $250 from mbrebel.com or you can search "teny rims" on ebay and get some of those. Just make sure they are disc brake compatible, cause hub adapters don't work on mag wheels unless you have access to a machine shop and can make your own. I've made my own disc adapters, but hub adapters are harder.Have you removed the governor system yet?Also do you know what RPM your clutch engages at? If it's more than about 3,000 or less than 2,200, you'll have issues.I'd recommend carefully re-reading all of the instructable and gaining a thorough understanding of what you're trying to build before you buy anything else.

Also, post some pics! Even if it's just the parts you have so far, I can probably make some recommendations.

If by transmission you mean a jackshaft for 2 stage gear reduction, then yes, you need a transmission. Unless you can fit like a 150 tooth rear sprocket, but that would be impractical, very expensive, and look ridiculous. Having a jackshaft will also help you to get proper sprocket alignment.

That bike appears to have wide cranks. You really want a steel frame, most aluminum frames do not last long with such a powerful engine. I found my red bike on craigslist for $150. I could have motorized it as-is and it would have turned out ok. However I upgraded just about everything on it, so it cost me a lot more. Front suspension is really nice to have though.

Yea, I figured if it went over 40 you might be a little lacking in acceleration. I find that for a rider like me who weighs about 155 pounds, a 13:1 gear ratio is pretty good if you're running 26" tires. What are the tooth counts on your current sprockets? Also what's up with the top bar of your frame? Did you cut it out and re-weld it to fit the engine?

Yea, right now your ratio is about 9.33:1, way too steep. Try a 30t or 32t in place of the 22t. Also that bike is really unsafe without a top bar. I would not ride it. You should get a new bike frame. The bike you linked to will most likely not fit a predator engine. Look for an old 21" steel frame mountain bike on craigslist, such as a trek 820. If you're having issues finding a large enough frame, some people have done vertical mounted predator engines, which will save some space, but will probably require you to get wide cranks.

Also if you want a better brake, you could attach a bicycle disc brake to the sprocket and space it out a bit so it will clear the chain.Sorry for the double post.Cool build btw.

If you want to race, remove the governor system from the engine and you will go twice as fast. The governor is only there to prevent you from blowing up your rototiller or snowblower or what-have-you. Removing it won't hurt the engine, but it will allow you to turn about double the rpm.

The golden eagle mount kit might be fine for smaller engines, but it looks a little flimsy to hold up to a larger engine. Also you would probably have to modify it a lot to get it to accept a predator engine, enough that it would probably be more work than just making one from scratch. Also $375 is a lot of money for just a mounting kit. You could buy all the metal and tools you'd need to build one from scratch for less. You can really get away with using only a drill and a handheld angle grinder with cutoff discs for mount fabrication, it won't look nice, but it will function fine. Also you can build the engine mount in a day easily, it takes me about 3 hours to put together an engine mount.Another thing I notice about the golden eagle mounting kit is that it has a belt drive which att...

The golden eagle mount kit might be fine for smaller engines, but it looks a little flimsy to hold up to a larger engine. Also you would probably have to modify it a lot to get it to accept a predator engine, enough that it would probably be more work than just making one from scratch. Also $375 is a lot of money for just a mounting kit. You could buy all the metal and tools you'd need to build one from scratch for less. You can really get away with using only a drill and a handheld angle grinder with cutoff discs for mount fabrication, it won't look nice, but it will function fine. Also you can build the engine mount in a day easily, it takes me about 3 hours to put together an engine mount.Another thing I notice about the golden eagle mounting kit is that it has a belt drive which attaches to the spokes. While this may be fine for sturdy wheels paired with a really small engine, the predator is powerful enough to rip the spokes out within the first 100 miles. Remember we are talking about an engine that is easily 4 times more powerful than any of the golden eagle engines. Also doing a rear mount for a larger engine is going to significantly raise your center of gravity and make it a lot easier to lose control.Another thing is that using the golden eagle kit, I have no idea what gear ratio the kit has, it might be completely wrong for a predator engine.Also IMO golden eagle is really overpriced, for the cost of some of their engines I could build a decent predator bike if I got lucky on craigslist; although there are some who swear by them as well. Make of that what you will.

Glad to see someone who might actually be interested in building one! So, first off, on the frame, it's an aluminum frame, which I don't like. Aluminum fatigues much faster than steel, leading to a broken frame rather quickly. The blue road bike that is in one of the intro pictures had an aluminum frame, which broke within a thousand miles. Also, if you buy a bare-bones frame with nothing else on it, expect to spend a LOT more on parts than if you just bought a craigslist bike and swapped out parts, especially if you need to have the shop build the bike for you.Second, on kit engines: I find that the Chinese 2 stroke kits are made as cheaply as possible, and contain many inferior parts that will require immediate replacing to get the bike running, and many more that will need to be repl...

Glad to see someone who might actually be interested in building one! So, first off, on the frame, it's an aluminum frame, which I don't like. Aluminum fatigues much faster than steel, leading to a broken frame rather quickly. The blue road bike that is in one of the intro pictures had an aluminum frame, which broke within a thousand miles. Also, if you buy a bare-bones frame with nothing else on it, expect to spend a LOT more on parts than if you just bought a craigslist bike and swapped out parts, especially if you need to have the shop build the bike for you.Second, on kit engines: I find that the Chinese 2 stroke kits are made as cheaply as possible, and contain many inferior parts that will require immediate replacing to get the bike running, and many more that will need to be replaced if you want to go more than 25 mph. For example, the stock sprocket that comes with the chinagirl engines attaches to your wheel by clamping onto the spokes. Not only does this provide no way of properly aligning the sprocket, but it will also quickly rip the spokes out of your wheel and pull it out of true. If you know a lot about 2 stroke engines, enjoy tinkering, and aren't looking for a reliable mode of transportation, but just something to have fun with, go ahead and get a 2 stroke kit for the first build. But know that if you want to hit anywhere near 35 or 40 mph, you will need to do a TON of engine modifications. I'm talking porting the engine, replacing and tuning the carb, welding your own exhaust pipe, and a bunch of other things. Also, unless you have a heavily modified and upgraded 2 stroke, you will have to choose between speed or hill climbing power. The engines simply aren't powerful enough to give you both.On my bikes: It looks harder than it is. Unlike the 2 stroke kits, the predator engines will start right out of the box, without any carb tuning or part replacement. The magneto will not die instantly if you get a bit of water on it. The spark plug boot and fuel line will not disintegrate in the sun. And, perhaps most importantly, I have provided you with extremely detailed instructions on how to build one. Also hitting 40 and still being able to climb most hills is easily within the grasp of the 79cc predator engine.Whatever you choose to build, I'd be happy to help you build it by answering questions, giving advice, and troubleshooting.The blue bike was my second build btw. My first was a 66cc 2 stroke kit. Black was my third, Red was the 4th.BTW, if you're wondering what would be a step up from the predator bikes... This is what I'm currently building.

I can't find the comment by nicolas that you're referring to. But I would like a contest that is specifically for smaller engines, I want to see people build motorized stuff. And have an excuse to build another motorized bicycle.

I think it reaches out to more people than a lot of the contests we have had lately. I'm talking about all the ones that pretty much require you to have stuff like 3D printers and other specialized equipment. Plenty of people love to tinker with small engines.

The chain tensioner you have already heard about, but I also feel the need to mention that the rag joint (the way the gear bolts to the spokes) will ruin your rear wheel pretty quickly. You should instead use a hub or disc brake sprocket adapter. For more information about disc brake mounted sprockets, check out steps 56-58 of my instructable, and also take a look at this image of the rear wheel of one of my motorized bikes.

Also you should consider replacing all the mounting bolts if you haven't already, they are usually made of chineseium, a mixture of plastic and aluminum, and will strip or break if you so much as look at them wrong.

Adding onto the "start a fire" step, if you unbend a coat hangar, hook it through the steel wool, light it on fire, and swing it around, it makes the brightest, most incredible sparkler you will ever see.

Engine porting is basically just doing a little quality control on the intake and exhaust ports. The way they come from the factory, there is often a lot of gunk and bits of metal sticking out, the holes are not smooth like they should be. This creates little eddies of air the restrict the amount of air which can be moved through them. Sometimes the ports are also not in quite the right places height-wise either. You can clean them up manually pretty easily. Do a search for engine porting on motorbicycling.com if you want more info on that. Here's a decent thread I found http://motorbicycling.com/showthread.php?t=16646. As for the spark plug lead, it is sometimes glued to the CDI, but it's not very good glue, and it just screws off, take a pliers and use it to twist the lead till it bre...

Engine porting is basically just doing a little quality control on the intake and exhaust ports. The way they come from the factory, there is often a lot of gunk and bits of metal sticking out, the holes are not smooth like they should be. This creates little eddies of air the restrict the amount of air which can be moved through them. Sometimes the ports are also not in quite the right places height-wise either. You can clean them up manually pretty easily. Do a search for engine porting on motorbicycling.com if you want more info on that. Here's a decent thread I found http://motorbicycling.com/showthread.php?t=16646. As for the spark plug lead, it is sometimes glued to the CDI, but it's not very good glue, and it just screws off, take a pliers and use it to twist the lead till it breaks the glue, then you can unscrew it and screw in a new one..